Data commit

Task/Middle-three-digits/Pascal/middle-three-digits.pas

@@ -0,0 +1,37 @@
+program Midl3dig;
+{$IFDEF FPC}
+  {$MODE Delphi} //result /integer => Int32 aka longInt etc..
+{$ELSE}
+  {$APPTYPE console} // Delphi
+{$ENDIF}
+uses
+  sysutils;   //IntToStr
+function GetMid3dig(i:NativeInt):Ansistring;
+var
+  n,l: NativeInt;
+Begin
+  setlength(result,0);
+  //n = |i| jumpless abs
+  n := i-((ORD(i>0)-1)AND (2*i));
+  //calculate digitcount
+  IF n > 0 then
+    l := trunc(ln(n)/ln(10))+1
+  else
+    l := 1;
+  if l<3 then Begin  write('got too few digits');  EXIT; end;
+  If Not(ODD(l)) then Begin write('got even number of digits'); EXIT; end;
+  result:= copy(IntToStr(n),l DIV 2,3);
+end;
+const
+  Test : array [0..16] of NativeInt =
+    ( 123,12345,1234567,987654321,10001,-10001,
+    -123,-100,100,-12345,1,2,-1,-10,2002,-2002,0);
+var
+  i,n : NativeInt;
+Begin
+  For i := low(Test) to High(Test) do
+  Begin
+    n := Test[i];
+    writeln(n:9,': ',GetMid3dig(Test[i]));
+  end;
+end.